WO2011141514A1

WO2011141514A1 - Fastening assembly for blades of turbomachines having axial flow and method for producing such an assembly

Info

Publication number: WO2011141514A1
Application number: PCT/EP2011/057628
Authority: WO
Inventors: Patrick Bullinger; Marco Link; Nicolas Savilius; Uwe Sieber; Hubertus Michael Wigger
Original assignee: Siemens Aktiengesellschaft
Priority date: 2010-05-14
Filing date: 2011-05-11
Publication date: 2011-11-17
Also published as: JP5596223B2; US20130101422A1; EP2569514A1; JP2013526667A; RU2012154199A; EP2386721A1; EP2569514B1; CN102906375A

Abstract

The invention relates to a fastening assembly (8) for blades (10) of turbomachines through which axial flow can take place, preferably compressors, comprising a blade carrier (20) having a lateral face, in which retaining grooves (22) are distributed along the circumference, with blades (10) being inserted in said grooves, wherein a resilient tensioning element (28) is provided between each groove base (24) and the underside (16) of the respective blade foot (14), said underside being located opposite of the groove base. The tensioning element is supported on the respective underside (16) and on the respective groove base (24) in a pretensioning manner, wherein a channel (18, 26) is provided both in the groove base (24) and in the underside (16), with the tensioning element (28) resting in said channels.

Description

description

Fastening arrangement for blades of axially flowed turbomachinery and method for producing such

The invention relates to a fastening arrangement according to the preamble of claim 1. Furthermore, the invention relates to a method for producing such a Befestigungsanord- tion.

The present invention relates to the mechanical connection of stationary or rotating blades of the flow path of an axial-flow turbomachine. These are vanes which are fastened to the housing or to a corresponding guide blade carrier or to rotor blades which are arranged on the rotor of the turbomachine. In a stator system of the prior art, vanes of a blade ring are mounted in a circumferentially extending groove. In rotating systems, it is known that rotor blades are inserted into a respectively associated ^¬ impaired, axially extending groove. For example, a resilient Be ^¬ fastening of moving blades in a circumferential groove of the turbine rotor is known from US 6,761,538 B2, which are pressed by means of a both längsgeschlitz ^¬ th and quergeschlitzten tubular spring element on the known hammer-shaped interlocking.

US Pat. No. 2,753,149 discloses a further type of fastening of compressor rotor blades to a rotor disk. To prevent movement of the compressor rotor blade along its axial groove, a double-headed bolt connection is provided between the groove base of the axial groove and the blade root underside. Nevertheless, a slight movement of the

To allow Verdichterlaufschaufei in the retaining, the bolt sits with a small clearance in his recording. In operation, however, such constructions tend to be one wear-generating blade rappers, especially at the start of the compressor.

In addition, a fastening arrangement is known from US 4,836,749, in which a shaft of a super-elastic

Material for tempering a blade is used. The inherently hollow stem is filled with a low melting temperature material and an electric heating element. The heat generated by the current flow then leads to radial expansions of the shaft, whereby a contact force is generated. However, this arrangement is complicated,

susceptible to faults and associated with operating costs.

The object of the present invention is to specify an alternative fastening arrangement for blades of turbomachines which can be flowed through axially. Another object of the invention is to provide corresponding manufacturing method.

The object relating to the fastening arrangement object is achieved by one which is designed according to the features of the on ^¬ claim 1. The manufacturing method of the ge ^¬ addressed object is solved both by a method according to claim 11 and by a method according to claim. 13

The mounting arrangement according to the invention for blades of axial throughflow turbomachine comprises a blade carrier having a central axis and a concentric jacket surface, in which along the circumference distributed holding grooves with an axial extension are provided and blades whose blade roots are inserted in these retaining slots where ^¬ at each Holding groove has a groove bottom, which is opposite to a lower ^¬ side of the respective blade root, and depending Weil ^¬ a resilient, arranged between each groove base and the underside of this opposite clamping element, wel ^¬ Ches is biased on the respective bottom and the respective groove base, wherein in the undersides of the blades are each provided with a groove, in which the relevant clamping element surface, that is applied along its longitudinal ^¬ extension. Preferably, a suitable groove for guiding the clamping element is arranged in the groove base. The invention is based on the finding that an improved contact pressure of the blade in the retaining groove can be achieved if at least on the blade root underside a channel is provided, in which the clamping element rests positively over its entire length. For a over the length of the undercut Verhakungsbereichs gleichmä ^¬ ssige contact pressure of the blade is achieved, which is not the case with the closest prior art. At the same time an increased process quality is achieved during assembly of the blade in the retaining, since an individual adjustment of blades for pressing and fixing is not required.

If a gutter is provided both in the blade root underside and in the groove bottom, these gutters can be produced particularly easily with the aid of the following methods.

After the first method, the blades and the blade carrier are made including all retaining grooves. Then the insertion of a blade takes place in the associated retaining groove. At ^¬ closing the blade is temporarily xed fi in the holding. This is followed by the pairs, ie simultaneous Her provide ^¬ of the two opposite grooves by a single drilling operation. The bore extends along the underside-groove bottom plane and cuts in half in the Schau ^¬ felfuß and in the blade carrier. Subsequently, the insertion of the clamping element takes place in the bore. It is preferably provided that the temporary fixation is released again before or after insertion of the tensioning element. With the help of this first method according to the invention, both channels can be produced simultaneously in a relatively simple manner and without unduly great expense. Since both channels are produced in only one drilling operation, it can be assumed that their position is very high in accuracy with respect to both channels, which results in a particularly reliable seating of the spring element in FIG causes the corresponding grooves. This has the consequence that with predetermined clamping forces the blade can be pressed in its retaining groove to the undercuts, in particular over the entire length of the undercuts.

A second method according to the invention comprises the following steps: first, the blade carrier is produced, but without the associated retaining grooves. Subsequently, a drilling of the blade carrier, wherein the holes are each placed in such a way that later in the manufacture of one of the

Held only a part of the surrounding hole in question material is removed. Subsequently, the retaining grooves are manufactured in the blade carrier, wherein in the meantime only a part of the material surrounding the respective hole is removed, so that the remaining part of the material surrounding the relevant hole forms the groove-side groove. Subsequently, the insertion of blades takes place, each with the underlying already existing ^¬ ner groove and the insertion of the clamping element in the space bounded by the opposing grooves space.

This production process has the advantage that the arranged in the shop ^¬ felträger channel can be preliminarily prepared relatively easily and without any special effort, in particular if the longitudinal directions of the channel and hold ^¬ are nut different.

Advantageous embodiments are specified in the subclaims.

According to a first advantageous embodiment, both grooves extend parallel to the longitudinal extension of the retaining groove. Alternatively, it can be provided that the grooves extend obliquely to the longitudinal extension of the retaining groove. The last-mentioned variant has the particular advantage that due to the mutually inclined displacement direction of blades (along the retaining groove) and clamping element (along the channel) a positive connection between the blade root and groove by means of Clamping element is brought about, which also serves as axial securing against displacement of the blades along the retaining groove. Thus, the clamping element is at the same time the Axialverschiebungssicherungsfunktion. At the same time, the shearing forces acting on the clamping elements by the blades prevent the latter from being released from the channels.

Appropriately, it is provided that the Längserstre- ckung of the retaining grooves relative to the central axis is inclined and the grooves extend parallel to the central axis.

In order to allow a comparatively simple assembly of blades and clamping element, the groove-side channel opens into at least one of the two end faces of the

Blade carrier, which adjoin the lateral surface.

And / or the bottom channel opens into at least one of the two end faces of the blade root, which adjoin the bottom. Accordingly, a lateral accessibility of the grooves for mounting the clamping element, which is preferably designed as a dowel pin, can be assumed.

In the event that the channels extend parallel to the Längserstre- ckung the retaining groove, it is provided that for securing the clamping element against the end-face loss Publ ^¬ voltage of one or more channels is caulked.

The proposed mounting arrangement is applicable to both rotating and static systems. In rotating systems, the blade is designed as a blade with axial feet and the blade carrier as a rotor element, wherein at least a portion of the radially outer shell ^¬ surface of the rotor element forms the respective lateral surface of the blade carrier with the corresponding retaining grooves. In static systems, each blade is formed as a vane with axial feet and the blade carrier as an annular vane support member, wherein at least a portion of the radially inner surface of the vane support forms the respective lateral surface of the blade carrier.

Of course, the aforementioned mounting arrangement is applied to all blades of a blade ring.

The invention will be further explained with reference to a drawing. Showing:

1 shows the perspective view of a blade root

a shovel for the inventive Fixed To ^¬ supply arrangement,

2 shows a perspective view of a portion of the fastening arrangement according to the invention with a holding groove and a blade seated therein,

3 shows the section through a blade carrier of a fastening arrangement,

4 shows a blade according to a second embodiment and

5 shows a blade carrier according to a second embodiment, suitable for receiving the blade shown in FIG.

FIG. 1 shows, in a perspective view, a blade 10 designed as a compressor blade. The compressor blade comprises an airfoil 12 which is only partially shown, to which a blade root 14 adjoins. The blade ^¬ foot 14 has an outer contour which swallowtail mig is adapted to be held in a blade carrier in FIG 1, not shown, form-fitting manner. The Schaufeififuß 14 has an underside 16, in which a

Channel 18 is arranged. The channel 18 will also be referred to below as the bottom channel 18. The lower side groove 18 extends over the entire longitudinal extent of the Blade root 14, so that it ends at the front side, dovetail-shaped contoured end surfaces of the blade root 14. In this case, the channel 18 is configured in a U-shape, that is to say in the shape of a groove with a semicircular basic contour, and is formed so deep that it can almost, but not completely, receive a clamping element, not shown, in the form of a tensioning pin. This makes it possible, the blade 10 by means of the clamping pin biased in a holding groove to tes ^¬ term, which has no groove-side groove.

FIG. 2 shows a perspective representation of a blade carrier 20 of a fastening arrangement 8. In the blade carrier 20, a retaining groove 22 is provided, which has a contour corresponding to the blade root 14 of the blade 10. In the area of the lower side channel 18 alone, the contour of the retaining groove 22 is not blade-footed but modified. In Nut ^¬ reason 24 of the retaining groove 22 is a groove-side groove 26 is provided. The blade 10 shown in FIG 2 under failed ^¬ det thereby from the position shown in FIG 1 the blade 10 is that the channel 18 is not U-shaped, but merely configured semi-circular. The openings of both channels 18, 26 face each other. Viewed in cross section, form both channels 18, 26 an approximately circular Kon ^{¬ structure} . They are also along their longitudinal extent always opposite each other and are thus suitable for receiving a clamping ^¬ element 28, which is usually designed as a dowel pin.

With the help of arranged in the grooves 18, 26 clamping pin 28 arranged on the blade root 14 supporting flanks 30 are pressed against each forming an undercut flanks 32 of the retaining groove 22, whereby the blade 10 is determined ^¬ holds radially. Both grooves 18, 26 extend over the entire axial extent of the retaining groove 22, so that the clamping element 28 is used frontally

(FIG 3). It should be noted that the clamping element 28 is shown only schematically in FIG 3, by the cross section is shown rotated in 90 °. According to an alternative fastening arrangement 8, whose

Shovel carrier 20 in FIG 5 and the blade root 14 are shown schematically in Figure 4, the grooves 18, 26 extend transversely, ie obliquely to the longitudinal extent of the holding 22. This has the consequence that the bottom channel 18 now not frontally opens in the blade root 14 but on the wing side (FIG. 4). Further, the groove-side groove 26 opens now not in the contour of the retaining groove 22, but outside of which as a bore opening. This is Darge provides ^¬ in FIG. 5 There, the mouth 34 of the nutgrundseitigen groove 26 outside the mouth 38 of the retaining groove 22. In particular, in the latter embodiment of the mounting assembly 8, it is advantageous if a bore is introduced at the point in the blade carrier 20 before producing the retaining groove 22, at which later the nutgrundseitige groove 26 should remain. Since the nutgrundsei ^¬ term trough 26 and retention groove 22 are aligned obliquely to each other at this point, can be after manufacturing of the retaining groove 22, the groove bottom groove disposed therein produce only very time-consuming conventional methods 26th

In the assembled state, the longitudinal displacement of the blade 10 along the retaining groove 22 is prevented by the fact that

Clamping element 28 on the one hand in a form-fitting manner in the bore or groove 26 and on the other hand also engages in the lower side groove 18 of the blade root 14. Due to the difference union under ^¬ displacement directions of the blade 10 - along the holding groove 22 - and of the clamping element 28 - along the bovine nen 18, 26 - is saved simultaneously with the insertion of the clamping ^¬ elements, the blade 10 against a displacement along the holding groove 22nd

Overall, a mounting assembly 8 for blades 10 of axial throughflow turbomachines, preferably compressors is specified with the invention, a blade ^¬ carrier 20 are provided with a circumferential surface, in which along the environmental distributed fangs retaining grooves 22 and comprising in which Blades 10 are used, wherein between each groove bottom 24 and the opposite bottom 16 of the respective blade root 14, a resilient clamping element 28 is provided, which is biased on the respective bottom 16 and the respective groove bottom 24, where ^¬ both in the groove base 24 and in the bottom 16 each have a groove 18, 26 is provided, in which the clamping element 28 abuts.

Claims

claims

1. mounting arrangement (8) for blades (10) of axially permeable turbomachinery,

full

a blade carrier (20) having a central axis and a concentric lateral surface, in which along the circumference distributed retaining grooves (22) are provided and blades (10) whose blade roots (14) in the retaining grooves

(22) are used,

wherein each retaining groove (22) has a groove bottom (24) which faces a lower side (16) of the respective blade root (14), and

between each groove bottom (24) and this gegenüberlie ^¬ ing bottom (16) each have a resilient clamping element (28) is provided, which is biased on the respective bottom (16) and on the respective groove base (24),

characterized in that

in the bottom (16) has a groove (18) is provided, in which the clamping element (28) rests along its longitudinal extent.

2. Fastening arrangement (8) according to claim 1

in which in the groove base (24), a further groove (26) is vorgese ^¬ hen, which the bottom groove (18) opposite.

3. fastening arrangement (8) according to claim 2,

wherein both grooves (18, 26) extend parallel to the longitudinal extension of the retaining ^¬ (22).

4. fastening arrangement (8) according to claim 2, wherein the two grooves (18, 26) extend obliquely to the Längserstre ^¬ ckung the retaining groove (22).

5. fastening arrangement (8) according to claim 4,

wherein the longitudinal extent of the retaining grooves (22) is inclined relative to the central axis and the grooves (18, 26) extend parallel to the central axis.

6. Fastening arrangement (8) according to one of claims 2 to 5,

in which the groove-side groove (26) terminates in at least one of the two end faces of the blade carrier (20), which adjoin the lateral surface

and or

in which the underside channel (18) terminates in at least one of the two end faces of the blade root (14), which adjoin the underside (16).

Fastening arrangement (8) according to one of claims 2 to

6

in the two pairs opposite each other grooves (18, 26) a substantially circular recess bil ^¬ the.

Fastening arrangement (8) according to one of the preceding claims,

in which the clamping element (28) is designed as a clamping pin whose axial length is approximately equal to the length of the channel (18, 26).

9. fastening arrangement (8) according to one of the preceding claims,

in which the clamping element (28) is caulked against loss for security.

10. fastening arrangement (8) according to one of the preceding claims,

each blade (10) being in the form of a blade and the blade carrier (20) being formed as a rotor element,

wherein at least a portion of the radially outer surface of the rotor element forms the respective lateral surface of the Schau ^¬ felträgers (20).

11. Fastening arrangement (8) according to one of claims 1 to 9,

wherein each blade (10) as a guide vane and the scene ^¬ felträger (20) designed as an annular vane carrier,

wherein at least a part of the radially inner circumferential surface of the guide blade carrier forms the respective lateral surface of the blade carrier (20).

12. A method for producing a fastening arrangement (8) according to one of claims 2 to 11,

comprising the successive steps

Producing the blades (10) and the blade carrier (20) together with all the retaining grooves (22),

Inserting a blade (10) into one of the retaining grooves (22),

Temporarily fixing the blade (10) in the retaining groove (22),

· Pairwise producing two opposing ones

Troughs (18, 26) by a drilling operation along a bottom groove bottom plane and

• Insert the clamping element (28) into the hole.

13. The method according to claim 12,

in which the temporary fixation is released before or after insertion of the tensioning element.

14. A method for producing a fastening arrangement (8) according to one of claims 2 to 11,

comprise the successive steps,

• Manufacture the blade carrier (20) without retaining slots

(22),

• drilling of the blade carrier (20), wherein the holes are each placed ^¬ weils such that only a portion of the bore surrounding material is removed in forming one of the retaining grooves (22)

• production of the retaining (22), respectively during which only a portion of which surrounds the hole in question material is removed so that the restli ^¬ che part of the surrounding the bore in question Materi ^¬ than the groove bottom groove (26) formed,

• Insertion of blades (10), each with already existing gutter (18) and

• Insertion of the clamping element (28) in the space of opposite gutters (18, 26) limited space.